I am in a similar position, Feb 28 2017 applicant. I was asked for my Sch A and background check again (an IRCC agent told me it is normal for them to ask for an updated Sch A), apparently they asked me in March last year but there is a glitch in the system where some people (including me) did not receive messages. They finally asked me again in January this year, so I have submitted an updated Sch A and all police certificates. I just spoke with an agent on the phone today and they confirmed they have received all my documents and they are now reviewing my background check. The agent told me that sometimes the status does not update on your MYCIC account for several days, sometimes not at all...
Best of luck to you